1. Technical Field of the Invention
The invention relates to a method and logical units for providing services in a mobile communication system wherein a number of calls with different bearer capabilities are handled.
2. Description of Related Art
When communicating via a mobile communication system, in some cases a subscriber is called by a third party or wants to communicate with a plurality of parties. The GSM (Global System for Mobile communication) communication system supports this by offering so called supplementary services, e.g. call waiting, call hold, call forwarding on busy subscriber and multi party call. All these services are provided by the network and are activated by the mobile user.
A core network consists at least of entities that provide support for the network features and telecommunication services. The support provided may include for example a functionality of the management of user location information, the control of network features and services, the transfer mechanisms for signalling and for user generated information.
In the following these definitions are used, user B is a user who is engaged in a call with a user A. User A is the mobile user who is provided by the network with the respective supplementary service or supplementary services. User C is a user, who originates a call to user A, or is called by user A.
Call waiting enables user A to receive a call from user C. The call from user C is put on call waiting and an indication is sent to user B. User B can put the call with user A on hold and accept the call from user C. He can also reject the call from user C so that this call can be forwarded by the call forwarding on busy subscriber service. If user B accepts the call from C, he can set up a multi party call including user A in the active call with user C (ETSI Standards GSM02.83 and GSM02.84, version 5.0.0, November 1996).
FIG. 11b shows an example of a multi party call between three users A, B, C. In this example the multi party call is active and handled by an conference call device CCD in a mobile services switching center MSC. A conference call device is a device that can connect more than two parties with each other at the same time.
The GSM communication system also offers packet switched data services as the GPRS (General Packet Radio Service). However there are still shortcomings in the setup of several calls in parallel, as it is still not possible for example to do an active speech call, Internet browsing and the reception of a fax at the same time.
To overcome these shortcomings, a so-called UMTS (Universal Mobile Telecommunication Service) is under development. One of the principles of this communication system is the provision of multiple calls, which means that one user is able to handle multiple calls at the same time (ETSI Standard UMTS 22.00 version 2.0.0, January 1999).
The UMTS (Universal Mobile Telecommunication System) communication system is capable of handling several calls to one mobile user equipment, the so-called multiple call capability. Opposite to a GSM (Global System for Mobile communication), the UMTS communication system neither releases a first call nor puts a first call on hold. The UMTS communication system sets up several calls in parallel to one mobile user equipment. This enables a mobile user to use several applications at the same time. For example a mobile user can have a speech call while receiving a fax and doing a data call. Even several calls of the same kind, as for example multiple data calls are possible. FIG. 11a shows an example of a possible implementation of a multiple call from a device B and a device C to a mobile user equipment A. In this example the multiple calls are handled in parallel by a mobile services switching center MSC.
It is a shortcoming of the known UMTS that there is no description how a mobile user can for example set up a speech call to two subscribers at the same time providing also a connection between these two subscribers.
It is a further shortcoming of the known prior art that there is no handling for the case that network resources for setting up multiple calls are exhausted.
Therefore it is an object of the present invention to provide a mobile user in a mobile communication system that supports a number of calls with the same or different bearer capabilities for one mobile user with additional services.
This problem is solved advantageously by the method of claim 1 and the logical units of claim 16 and 17.
It is advantageous that the air interface between a mobile user equipment and the core network is used for only one call and by that uses the radio resources more efficiently, this enables an operator to offer more calls at the same time.
Further advantageous is that the communication system and the mobile user equipment provide more flexibility of call handling to the mobile user, in that the mobile user can decide on a per call basis how the user wishes to accept a new call.
It is further advantageous, that the mobile user equipment has to use fewer calls, this saves battery power and increases the stand-by time and active call time of a mobile user equipment.
Another advantage is that the system uses services known to a mobile user familiar with GSM, this reduces the time a user needs to accept and get used to the new system.
It is further advantageous that the system uses services known to a mobile user familiar with GSM. This reduces the time a user needs to get used to the new services and it reduces the time until a new user makes use of the new services.
It is advantageous that the connection hardware is placed in the core network instead of having it into the mobile user equipment, this reduces the costs and the size of the mobile user equipment.
Further advantageous embodiments of the invention are found in the claims 2 to 15 and claims 18 to 23.
It is advantageous according to the depending claims that the user defined settings for taking a decision, whether a call should be set up as a new parallel call, a call should be put on hold or a call should be rejected can be defined once for all further calls, this makes the use of the service more comfortable for a mobile user.
Another advantage according to the depending claims is that the user defined settings for taking a decision, whether a call should be set up as a new parallel call, a call should be put on hold or a call should be rejected can be defined before each originating call, this makes the use of the service more flexible for a mobile user.
Further advantageous is according to the depending claim that the user defined settings for making a decision, whether a call should be set up as a new parallel call, a call should be put on hold or a call should be rejected can be defined before each first attachment to a mobile communication system that supports multiple calls, this offers a good compromise between the flexibility and convenience of the service.
Further advantageous is according to the depending claim that the decision logic is fully implemented in the mobile user equipment, this reduces the necessary processing in the core network and improves the performance of the core network so that the core network can handle more call attempts in the same time.
Another advantageous according to the depending claims is that the decision logic is fully implemented in the mobile user equipment, this reduces the necessary transfer of information between the mobile user equipment and the core network and allows more chargeable traffic on the air interface.
Further advantageous is according to the depending claims that the decision logic is partly implemented in the core network, this reduces the necessary signalling in the case that a terminating call is attempted to the mobile user equipment.